Chair iron



July 2l,x1946. H, w. SHELDRICK Efrm. 2,403,193

CHAIR IRQN -Film1 June e, 1.944 2 sheets-'sheen 'la f m@ Patented July 2, 1946 Gardner, Mass., assignors to Collier-Keywortl Company', Gardner, Massi, a corporation of YMassachusetts Applicationgrunea, 1944, serial No; 538,970

6 Claims.

This invent-'lon relates to chairs Vof the type embodying-a pivotally' mounted' seat and back such, for example, as 4o 'ilicechairs and the like.

The principal Vobjects of the invention are to provide an improved "chair iron for supporting the seat and back for simultaneous .controlled movement `and to provide 'an v.efficient and reliable means for quickly and conveniently adjusting the relative movements of the seat kand back so as to suit the com fort'of'the occupant. Y

vOther objects relate'to various features of construction and will be apparent from the consideration of the following description and by the` ac companyingdrawings,wherein iV Fig. l is a side elevation of achar embodying thprese'nt invention; v

. Fig. 2 is a Central ,vertical sectional elevation through the chair iron;

rvFig. 3 is la top plan view of the chair iron;

Fig. 4 is a plan AView of `a plate Vmember associated with the adjustable links; and

Fig. 5 is a detail showing, the slotted links assembled with theA locking plate ofj Fig. fl.

In accordance'with the Vpresent invention We provide a chair lcomprising a b ase i member which may beof any conventional design construction, separate seat and vback nienfrloeifs which `may also be of conventional design and construction,

, 2 maintain `the seat and back in substantial'ly horizontal and vertical positions, rrespectively,l also is capable of adjustment so that Vthe iorfce required vto effect tipping movement .of the seat vvand back may be varied. In the embodiment 'herein shown iorfthe purpose of illustration, a conven .tional base. or pcd;- estal I is supported on casters 2, and a chair iron 3, carried by the base, supports separateseatand back members 4 and 5. The seat Aand back bers may be O f Grivetoal design ,and constmf Y tion, c being understoodltnaihe .backrest .5

by the base member and supporting Aboth theseat and back lfor tipping movement 'which .may be readily controlled by adjusting certain parts of the chair iron, thereby securing, Withilllimits, the K desired angular relationship between the seat and back which is lmost `conducive cto. the comfort The chair iron 4orjsuppnting mechanism ycornprises a plurality'of interconnected members con.. structed and: arranged? so asto provide, in eilect,

a four-bar linkage wherein oneof "the --links is rigidly xed tothe base, another' linknormally supporting the 'seat in a substantially horizontal position, a third link supporting 'theiback in an upright position, anda pair of pivotaljly'connected slotted links interconnected with a slotted plate,

festive length of the adjustable 1mi;A 'thefangie er inclination' v of 4the back and relative movements of thejse'at and. back may be varied asdesir'edgv In addition we also provideineans for yieldingly Opposing' .tipping Arnc:vement ofthe seat and back. which'meansnot only is eilective'normally t0 is pivotallysupported independently'of the ,seat

4, as hereinafter described.v

The chair iron 3 comprises a fixed memberl having upstanding sidewalls I I and I 2, A and vis swivelly mounted on Aa kpivot I3 projecting upwardly from the cap 8 of the pedestalythe iixed member I0 being forwardly'inclined as shovvnjin Figs. `l and 2, The upper forward end ofthe fixedmember I0' carries a laterally projecting pivot pin Ikon which the Is eat-supporting mein,- ber l5 is ,rzvtellymoeted' The ,Seatsupporte ing member vI 5 comprisesapair of spaced, parallel angle ,irons 'I6 rigidly secured, @whe imei and rear ends by crossbars v'I'I and I 8, the seatsupporting memberbeine'mounied 0.11 the pivot 1.4i at a point adjacent to but spaced inwardly from the front end of the seat, as Vshown more clearly in Fig. 1. The seat 4 is Vscrewed or otherwise suitably attached `to. the anglevirons I6 and/or crossbars I'I and I8, the seat'b'eing thus supported fortipping'ririoveinentV about the pivot p inIII. The rear-'end of the seat-,Supporting member is pivotally connected by a pin Av2Il tothe upper" end of a Ivertically depending back-supporting member V2| of substantially `U-shape'cross-sectiin which` provides side Walls 22 and v23 having aligned openings for the reception of the Vends of pivot 2). Thefback rest 5 is adjustably secured to the outer face of `the member 2| in any suitable manner, here shown as comprising a clamping me'cl'ianisml 24', operated by'handYWheel '25, for adjustably positioningthe back 5 vertically with respect to the seat f4. Since such meclif anism is'Well known to those skilled in theart,

a description thereof is unnecessary.

The back-supporting member 2-I is connectedlto the fixed member I!! by apair ofv spaced'a`djust able members 3i) {Which together constitutein* elicot, a link member of adjustable length. 1Each r of the members 30 comprises a pair off-.slotted links 3l. `3,2 .and an, interposed lecliingtlat 34,

as snowpinrigs.; and .Asma or, rivetggas' carried by the outerl link 313" extends" through one Y are released softhat of the'arcuate slots 36in the plate 34 and the a stud 38 carried by the inner link 32 extends through the arcuate slot 31 of plate 34 and the slotted portion of the outer link 3|, thus providing Y pin and slot connections adjacent to the ends of the links, which'permit the links 3l, A32 tobe veX- tended or .retracted relative to each other The rear ends of therouterlinks 3| are pivotally con-jV nected to the Yback-supporting member by rivets or studs 4U and the front ends of the inner links .32 are pivotally connected to the fixed member Y I by rivets or studs 4I, as shown in Figs. l to 3.

' slotted portion of the inner link 32, and similarly A spindle 42 extends transversely through each adjusting member 30, projecting through Vthe in-.

ner ends of the'slots in the links 3|. 32 anda .central opening 43 in the plate 34.k One end of the spindle is formed with ahead 44 (Fig. 3)` which provides an'annular shoulder adapted to yengage the marginal portions about theslot in one ofthe outer 1inks3l, and the opposite end of the spindie'is threaded to reoeiveihe hub 45 (Fig. 3)'y of a hand wheel'46; The intermediate portion ofthe spindle 42, i. e., the part disposed between the two adjusting members 30, carries a sleeve 48 (Figs. 2 and 3) the opposite ends of which engage thev inner. links 32.V When Ythe hand wheel 45is tightened the inner end ofthe hub` 45 and head 'i V44 cooperate with the ends vof the sleevel 48 toY clampthe links 3 l, 32 and plate 34 together= thus Y frictionally locking the parts; and when the hand wheel 46 is unscrewed or loosened, these parts the `links 3|, 32 may beek; tended orretracted.v .5

'.When the links 3|,. 32 are retracted ori-exitended, the' plate 34 -is rotated Vin one direction or the other, as indicated in Fig. 5, due to the engag'ement of the studs 35, 38 with the walls of the slots 35, 31, the magnitude ofgthe relative movementofithe links 3|, .32 in either direction being determined by the length 0f the slots 36, 3T-.rand y' their. angular Aposition vvithY respect to; the open# ing. 43. ,As here shown, the slots 36, ,31 are arcuate and. eccentric Vwith respect to the circular Yopen? ing 43 so that-the links 3|, 32-may undergo a preev Y determined relative movement in traveling from Vfully extended position, as shown 4by the full lines ofFig'.5,to fully retracted position, as shown by the dot and dash Vlines of Fig. 5. In this embodie ment the Vslots 36 in the plate 34 are so shaped and located that a great part` ofthe thrust causedby the force applied to the links in any effort to eX- ltend or retract them is taken up by the pressure f the studs 35 and 38 against the outerv or inner edges of the'slots 36 and 31. The amount of force porting member 2| and the relative movements of the seat and back-supportingmembers maybe controlled or adjusted to suit theccmfort of the occupant by varying theeiective length' of the adjustable members 30in the manner above described. It Will be observed that due to the con venient locationjrof the hand wheelfsuch adjustments may readilybe made by the occupant while seated in the chair. Y Y

Y In order yieldingly to restrain tilting movement ofthe seat and back and effect the return of theseparts from fully tilted to normal position,

Y any suitablel resilient/means acting on the xed member and anyof the movable members may 4be employed..- Ashere shown (Fig. 2), the lower wall of the fixed member I0 is formed with an, opening surrounded by a boss or hub 5| to provide a seat for one end of a coil compression spring 52; A U-shaped depending extension i,

member 54, rigidly secured to the angle iron'IB of the seat-Supporting member.l5, extends about the lower wall of the iixedvmember I 0as shown in Fig.,2, Yand an opening 55=-formed 'o-n the ex#v f tension member 54. aligns .with theopeningy. A bolt orY screw shaft. 55 extends aXiallyv through the spring 5.2 and the kvopen-ings .50.a1'id'155, and its headed end carries alwasher 5'l-,gagainstwhich the other endfof the spring 52n actsthe-threaded end of .the boit vprojectingoutwardly beyond. the

rextensiim member:` 5,4'. A washer-likeplate vfill.' preferably of hardened steel'and formed with` diametric'ally disposedv recessed portionsofk grooves 6|,.is positioned against thefouterA- face`V of the'extensionand a yoke 62' is carried bythe bolt 55With its tapered legs extendingintogthe recesses, as shown in Figs..l and 2.: vA washerv may be interposed between the youter end ofthe yoke s2 and .the hub of a hand wheeilssloarried by the threaded end ofthebol-t. By rotating the hand Wheell 68 ina clockwisedirection, the spring 52 may be compressed, thus .urging the U-shapeolY extension and fixed members together and.` consequently yieldingly opposing 'tilting' movement of the seat back Vwith a force ,dependent upon the 'degreeof compression of thesspring 52.. The taperedllegs of the yoke 62 provide apivotfpoint or km'fel edge on which thev spring .boltassemblyvis free .torock as the dangle betweenthefcenter i,sion 54 changesas the. seat is tilted.V With this 'construction and arrangement he hand wheel 68 ,may be rotated in one direction line ofthe bolt and thefront facefof the exten..

Vor another'toivary theaction of the spring .52',

which the device will withstand without slipping Yvent objectionable binding of the parts whenthe .hand-,wheel is loosened, thus insuring a smoother .operation than otherwise possible. y 1 :l With thisconstruction and arrangement and `Xedinember I0,the seatand Vbacksupporting members l5 and 2|, and the Yadjustable membersl '30, being pivotally interconnected'as above de-v scribed, constitute in effect a four-bar linkage, in

which the angle of inclination of the back-sup;-

theseat Y YV ,y v y. It will be noted thatin a chair constructed in thus permitting thev seat and'backfto bef'tilted under conditions controllable bythe occupant to suit his comfort. It will be observed-.thatithe hand wheel 68, being locaiedbeneathiho.seam, is readily ac'cessiblefor convenient manipulation and that'fwhen lthe' proper, adjustment '.ofthe. spring 52 vhas'been` made'gthe hand WheelA 68i is frictionally flocked against accidental rotation;

It Will also be ObS'eI'Vedthat the handwheels 25 and 46 (are. likewise locked for 'convenient manip-f` ulationv by the. occupant and hence the-height and angular'A position ofthe Aback A5,'. as Well-as thetilting actionl permittedlb'y, .the spring 52,

mayv be readily controlled lby aperson occupying accordance with the .presentinventionv the., front edge of'the seat does notv rise apDreci'ably-When the origins, tilted' from .normar horizontal .poen

iront yDue to. the"Y arrangement of..th'efinernbers of 'liberar-bar liinkagesesiupeeaa .verres i weight may sit comfortablyin the chair: without occupant, ratherv than by the weight of the (iccupant on the seat.

Whilewe have shown anddescribed one desirable embodiment of the invention, it is to be understood that this disclosure is for the purpose of illustration and that various changes in shape, proportion and arrangement of parts, as well as the substitution of equivalent elements for those herein shown and described, may be made without departing from the spirit and scope of the invention as set forth in the appended claims.

We claim:

l. In a chair of the type having separate seat and back members, a chair iron for supporting the seat and back members for simultaneous tipping movement, comprising a xed member, a seat-supporting member pivotally connected to said fixed member, a back-supporting member pivotally connected to said seat-supporting member, and adjustable means` comprising a locking plate, a pair of relatively slidable'links pivotally interconnected with the locking plate interposed between said links and means for locking the links and plate together, one of said links being pivotally connected to said fixed member at a point spaced from the pivotal connection with said seat-supporting member and the other of said links being pivotally connected to'said backsupporting member at a pointspaced from the pivotal connection with said seat-supporting member.

2. In a chair of the type having separate seat and back members, a chair iron for supporting the seat and back members for simultaneously tipping movement, comprising a fixed member, a seat-supporting member pivotally connected to said xed member, a back-supporting` member pivotally connected to said seat-supporting member, adjustable means comprising a looking plate, a pair of relatively slidable links pivotally interconnected with the locking plate interposed between said links and means for locking the links and plate together, one of said links being pivotally connected to said iixed member at a point spaced from the pivotal connection with said seat-supporting member and the other of said links being pivotally connected to said back-supporting member at a point spaced from the pivotal connection with said seat-supporting member and means associated with the fixed member and seat-supporting member for yieldingly opposing tipping movement of the seat and back members.

3. In a chair of the type having separate seat and back members, a chair iron for supporting the seat and back members for simultaneously tipping movement, comprising a xed member, a seat-supporting member pivotally connected to said fixed member, a back-supporting member pivotally connected to said seat-supporting member, and adjustable means comprising a `pair of linksi being ',pimta'JIveOnnected *.to vsaidqixed,

member 4.and Atheend of :the other .link being .pivotally connected. to said back-supporting member, a locking plate interposed betweenand' pivotally connected .to said' links, and clamping meansfor friotional'ly locking .the links and plate together to prevent sliding movement of the linksfrom a. selected position of adjustment.

4. In a chair of the type having separate seat and back members, a chair iron for supporting the seat and back members for simultaneous tipping movement, comprising pivotallyiinterconnected seatl and back-supporting members, a fixed member pivotally connected to said seatsupporting member, and adjustable means comprising a pair of relatively slidable links having pin and slot connections with each other, a locking plate interposed between and pivotallyvconnected to said links and clamping means for ririctionally locking the links in any selected position of adjustment, the end of one of the links being pivotally connected to the fixed member and the end of the other of said links being piv-v otally connected to said back-supporting member, said xed member, slidable links and the seat and back-supporting members being arranged to provide a four-bar linkage system wherein the position of adjustment of said slidable links determines the angle of inclination of the back and controls the tipping movement of the back relative to the seat. y K

5. In a chair of the type having separate seat and back members, a chair iron for supporting the seat and back members for simultaneous tipping movement, comprising pivotally interconnected seat and back-supporting members, a fixed member pivotally connected to said seatsupporting member, and adjustable means comprising spaced pairs of relatively slidable links, each pair of links having slotted portions at their adjacent ends and a plate interposed between each pair of links, said plate having a central opening and slotted portions at opposite peripheral margins, studs passing through the slotted portions of said links and plate to provide pin and slot connections therebetween, a spindle passing through the slotted portions of said links and the central opening in said plate, and locking means associated with said spindle to hold said links in any selected position of adjustment, corresponding ends of the links of each pair being pivotally connected to the fixed member and back-supporting member so that said fixed memnections with each other, the end of one of the ber, slidable links and the seat and back-supporting members provide, in elTect, a four-bar linkage system wherein the position of adjustment of said slidable links determines the angular position of said back and controls the tipping movement of said back relative to said seat.

6. In a chair of the type having separate seat and back members, a chair iron for supporting the seat and back members for simultaneous tipping movement, comprising pivotally interconnected seat and back-supporting members, a xed member pivotally connected to said seatsupporting member, and adjustable means comprising spaced pairs of relatively slidable links, each pair of links having slottedportions at their adjacent ends and a plate interposed between each 'pair of links, said plate having a central opening and slotted portions at opposite peripheral margins, studs passing through the slotted portions of said links and plate to provide pin yand slot connections therebetween, a spindle exvportions of "said links and the centralr openings in said plates,'one end of said spindle having' a,

Vhead member providing an annular shoulder engageable With the outer link of one pair, a sleeve circumposed about the intermediate portion of said spindle so that its opposite ends are engageable with the inner links of each pair, and 'a hand wheel having a threaded engagement` with lthe opposite end of said spindle and having a hub portion engageable with the outer link of the adjacent' pair, said spindle, sleeve and'hand Wheel being operative'rfrictionally to lock said links and plates together so as' to hold said vlinks in' any selected position of adjustment, the correspondslidable links and the seat and back-supporting members providing, `in eiect, a four-bar linkage system wherein the position vof adjustment of said slidable links determines the Vangular posi- Ytion of said back and controls they tipping vmovement of said back relative to saidseat. l

HENRY W.VSHELDRICK. f WILLIAM?. HOGLUND. 

